1. Field of the Invention
The invention relates to a transducer, more particularly to an ultrasonic sensor device that incorporates the transducer.
2. Description of the Related Art
Shown in FIG. 1 is a conventional ultrasonic sensor device. The ultrasonic sensor device includes a housing 1 with a connecting portion 2, and a transducer 3. A circuit board 11 is disposed in the housing 1. As shown in FIG. 2, the transducer 3 has a casing 31 formed from aluminum, a piezoelectric member 32 disposed on top of a bottom wall of the casing 31, a relaying circuit board 33 disposed above the piezoelectric member 32, and a conductive wire set 34 that electrically interconnects the circuit board 11 and the relaying circuit board 33. The relaying circuit board 33 is further electrically connected to the piezoelectric member 32 via a first connecting wire 36, and to the casing 31 via a second connecting wire 37. The piezoelectric member 32 is operable to generate a sensing signal, which is received by the relaying circuit board 33 and transmitted to the circuit board 11 via the conductive wire set 34. The circuit board 11 is operable to process the sensing signal to generate a processed signal and is mounted with a connecting pin set 12 that includes two connecting pins, which serve to output the processed signal and to connect to ground, respectively.
However, such configuration of the conventional ultrasonic sensor device has some drawbacks. For example, connection between the second connecting wire 37 and the casing 31 is typically by soldering, but the casing 31 is made from a material (aluminum) with a very high melting point. Moreover, the conductive wire set 34, the first connecting wire 36, and the second connecting wire 37 are also connected by soldering, thereby making the manufacturing procedure more difficult. Additionally, the sensing signal generated by the piezoelectric member 32 is relayed by the relaying circuit board 33 before being transmitted to the circuit board 11 for processing. It is preferable that the sensing signal be transmitted directly to the circuit board 11 in order to avoid signal attenuation.